Ten years of TRALI mitigation: measuring our progress

Preservation of recipient plasma sphingosine-1-phosphate levels reduces transfusion-related acute lung injury

Cold-stored (CS) platelets are once again being reintroduced for clinical use. Transfused CS platelets offer benefits over room temperature-stored (RTS) platelets such as increased hemostatic effects and prolongation of shelf-life. Despite these advantages little is known about their association with transfusion-related acute lung injury (TRALI). TRALI is associated with prolonged storage of RTS platelets and has a mortality of >15%. Determining the safety of CS platelets is important considering their proposed use in TRALI-vulnerable populations with inflammation such as surgical patients or patients with trauma. Donor platelet-derived ceramide causes TRALI, whereas donor platelet sphingosine-1-phosphate (S1P) is barrier protective. Females have higher plasma levels of S1P than males. Cold temperatures increase S1P levels in cells. Therefore, we hypothesized that female (donors or recipients) and/or CS platelets would decrease TRALI. To test this, we compared how male and female donor and recipient allogeneic platelet transfusions of CS (4°C) versus RTS (23°C) platelets stored for 5 days influence murine TRALI. Transfusion of CS platelets significantly reduced recipient lung tissue wet-to-dry ratios, bronchoalveolar lavage total protein, lung tissue myeloperoxidase enzyme activity, histological lung injury scores, and increased plasma sphingosine-1-phosphate (S1P) levels compared with RTS platelet transfusions. Female as opposed to male recipients had less TRALI and higher plasma S1P levels. Female donor mouse platelets had higher S1P levels than males. Mouse and human CS platelets had increased S1P levels compared with RTS platelets. Higher recipient plasma S1P levels appear protective considering females, and males receiving platelets from females or male CS platelets had less TRALI.NEW & NOTEWORTHY Transfusion-related acute lung injury (TRALI) though relatively rare represents a severe lung injury. The sphingolipid sphingosine-1-phosphate (S1P) regulates the severity of platelet-mediated TRALI. Female platelet transfusion recipient plasmas or stored platelets from female donors have higher S1P levels than males, which reduces TRALI. Cold storage of murine platelets preserves platelet-S1P, which reduces TRALI in platelet-transfused recipients.

The incidence of transfusion-related acute lung injury using active surveillance: A systematic review and meta-analysis

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-related mortality. A concern with passive surveillance to detect transfusion reactions is underreporting. Our aim was to obtain evidence-based estimates of TRALI incidence using meta-analysis of active surveillance studies and to compare these estimates with passive surveillance.

STUDY DESIGN AND METHODS

We performed a systematic review and meta-analysis of studies reporting TRALI rates. A search of Medline and Embase by a research librarian identified studies published between January 1, 1991 and January 20, 2023. Prospective and retrospective observational studies reporting TRALI by blood component (red blood cells [RBCs], platelets, or plasma) were identified and all inpatient and outpatient settings were eligible. Adult and pediatric, as well as general and specific clinical populations, were included. Platelets and plasma must have used at least one modern TRALI donor risk mitigation strategy. A random effects model estimated TRALI incidence by blood component for active and passive surveillance studies and heterogeneity was examined using meta-regression.

RESULTS

Eighty studies were included with approximately 176-million blood components transfused. RBCs had the highest number of studies (n = 66) included, followed by platelets (n = 35) and plasma (n = 34). Pooled TRALI estimates for active surveillance studies were 0.17/10,000 (95% confidence intervals [CI]: 0.03-0.43; I2  = 79%) for RBCs, 0.31/10,000 (95% CI: 0.22-0.42; I2  = <1%) for platelets, and 3.19/10,000 (95% CI: 0.09-10.66; I2  = 86%) for plasma. Studies using passive surveillance ranged from 0.02 to 0.10/10,000 among the various blood components.

DISCUSSION

In summary, these estimates may improve a quantitative understanding of TRALI risk, which is important for clinical decision-making weighing the risks and benefits of transfusion.

Transfusion-Related acute lung injury (TRALI) caused by antibodies to HLA-DRB1* 07:01 and HLA-DQB1*02:02: A case report

Transfusion-related acute lung injury (TRALI) is characterized by non-cardiogenic pulmonary edema and acute hypoxemia. There are few reports of HLA-II antibodies causing TRALI in China.

Update on transfusion-related acute lung injury: an overview of its pathogenesis and management

Transfusion-related acute lung injury (TRALI) is a severe adverse event and a leading cause of transfusion-associated death. Its poor associated prognosis is due, in large part, to the current dearth of effective therapeutic strategies. Hence, an urgent need exists for effective management strategies for the prevention and treatment of associated lung edema. Recently, various preclinical and clinical studies have advanced the current knowledge regarding TRALI pathogenesis. In fact, the application of this knowledge to patient management has successfully decreased TRALI-associated morbidity. This article reviews the most relevant data and recent progress related to TRALI pathogenesis. Based on the existing two-hit theory, a novel three-step pathogenesis model composed of a priming step, pulmonary reaction, and effector phase is postulated to explain the process of TRALI. TRALI pathogenesis stage-specific management strategies based on clinical studies and preclinical models are summarized with an explication of their models of prevention and experimental drugs. The primary aim of this review is to provide useful insights regarding the underlying pathogenesis of TRALI to inform the development of preventive or therapeutic alternatives.

The impact of revised definitions for transfusion-associated circulatory overload and transfusion-related acute lung injury on haemovigilance reporting

BACKGROUND AND OBJECTIVES

Transfusion-associated circulatory overload (TACO) and transfusion-related acute lung injury (TRALI) are serious adverse transfusion reactions. Standardized surveillance definitions are important to ensure consistent reporting of cases. Recently, revised definitions have been developed for TACO and TRALI, the latter of which has not yet been widely implemented. This study aimed to assess the impact of the new TACO and TRALI definitions on haemovigilance reporting.

MATERIALS AND METHODS

The Australian Red Cross Lifeblood Adverse Transfusion Reaction database was accessed to identify all cases of suspected or confirmed TACO and TRALI referred from 1 July 2015 to 30 June 2019. Cases were assessed against both the former and new definitions and the results were compared.

RESULTS

A total of 73 cases were assessed. There were 48 TACO cases identified. Only 26 of 48 cases strictly met the former 2011 International Society of Blood Transfusion (ISBT) definition of TACO; 6 cases did not meet the definition and 16 cases lacked sufficient clinical details. In comparison, 46 cases met the revised 2018 ISBT definition, with only 2 cases having insufficient details. There were 24 cases of TRALI according to the existing 2004 Canadian Consensus Conference (CCC) definition compared with 25 cases according to the proposed 2019 revised definition.

CONCLUSION

The revised TACO definition captured more cases than the former definition. No significant differences were observed in the number of TRALI cases under the proposed new definition. This is the first study to provide validation data for the revised TRALI definition.

What Is Different in Acute Hematologic Malignancy-Associated ARDS? An Overview of the Literature

Background and Objectives: Acute hematologic malignancies are a group of heterogeneous blood diseases with a high mortality rate, mostly due to acute respiratory failure (ARF). Acute respiratory distress syndrome (ARDS) is one form of ARF which represents a challenging clinical condition. The paper aims to review current knowledge regarding the variable pathogenic mechanisms, as well as therapeutic options for ARDS in acute hematologic malignancy patients. Data collection: We provide an overview of ARDS in patients with acute hematologic malignancy, from an etiologic perspective. We searched databases such as PubMed or Google Scholar, including articles published until June 2022, using the following keywords: ARDS in hematologic malignancy, pneumonia in hematologic malignancy, drug-induced ARDS, leukostasis, pulmonary leukemic infiltration, pulmonary lysis syndrome, engraftment syndrome, diffuse alveolar hemorrhage, TRALI in hematologic malignancy, hematopoietic stem cell transplant ARDS, radiation pneumonitis. We included relevant research articles, case reports, and reviews published in the last 18 years. Results: The main causes of ARDS in acute hematologic malignancy are: pneumonia-associated ARDS, leukostasis, leukemic infiltration of the lung, pulmonary lysis syndrome, drug-induced ARDS, radiotherapy-induced ARDS, diffuse alveolar hemorrhage, peri-engraftment respiratory distress syndrome, hematopoietic stem cell transplantation-related ARDS, transfusion-related acute lung injury. Conclusions: The short-term prognosis of ARDS in acute hematologic malignancy relies on prompt diagnosis and treatment. Due to its etiological heterogeneity, precision-based strategies should be used to improve overall survival. Future studies should focus on identifying the relevance of such etiologic-based diagnostic strategies in ARDS secondary to acute hematologic malignancy.

Adverse transfusion reactions and what we can do

INTRODUCTION

Transfusions of blood and blood components have inherent risks and the ensuing adverse reactions. It is very important to understand the adverse reactions of blood transfusion comprehensively for ensuring the safety of any future transfusions.

AREAS COVERED

According to the time of onset, adverse reactions of blood transfusion are divided into immediate and delayed transfusion reactions. In acute transfusion reactions, timely identification and immediate cessation of transfusion is critical. Vigilance is required to distinguish delayed responses or reactions that present non-specific signs and symptoms. In this review, we present the progress of mechanism, clinical characteristics and management of commonly encountered transfusion reactions.

EXPERT OPINION

The incidence of many transfusion-related adverse events is decreasing, but threats to transfusion safety are always emerging. It is particularly important for clinicians and blood transfusion staff to recognize the causes, symptoms and treatment methods of adverse blood transfusion reactions to improve the safety. In the future, at-risk patients will be better identified and can benefit from more closely matched blood components.

Treatment of bleeding in patients with liver disease

Patients with cirrhosis frequently have complex alterations in their hemostatic system. Although routine diagnostic tests of hemostasis in cirrhosis (platelet count, prothrombin time, fibrinogen level) are suggestive of a bleeding tendency, it is now widely accepted that these tests do not reflect hemostatic competence in this population. Rather, patients with cirrhosis appear to have a rebalanced hemostatic system with hypercoagulable elements. Therefore, routine correction of hemostasis laboratory values, for example by fresh frozen plasma or platelet concentrates, with the aim to avoid spontaneous or procedure-related bleeding is not indicated as is outlined in recent clinical guidance documents. However, little guidance on how to manage patients with cirrhosis that are actively bleeding is available. Here we present three common bleeding scenarios, variceal bleeding, post-procedural bleeding and bleeding in a critically ill cirrhosis patient, with specific management suggestions. As patients with cirrhosis generally have adequate hemostatic competence and as bleeding complications may be unrelated to hemostatic failure, prohemostatic therapy is not the first line of management in bleeding patients with cirrhosis, even in the presence of markedly abnormal platelet counts and/or prothrombin times. We provide a rationale for the restrictive approach to prohemostatic therapy in bleeding patients with cirrhosis.

Update on the pathophysiology of transfusion-related acute lung injury

PURPOSE OF REVIEW

The aim of this study was to discuss recent advances regarding the pathogenesis of transfusion-related acute lung injury (TRALI), which highlight the pathogenic role of macrophages.

RECENT FINDINGS

TRALI remains a leading cause of transfusion-related fatalities, despite the success of the mitigation strategy, and therapeutic approaches are unavailable. Neutrophils (PMNs) are recognized pathogenic cells in TRALI. Macrophages have previously also been suggested to be pathogenic in mice via binding of C5a to their C5a-receptor, producing reactive oxygen species (ROS), which damages the pulmonary endothelium. Recent work has further highlighted the role of macrophages in the TRALI-pathogenesis. It has been shown that the protein osteopontin (OPN) released by macrophages is critical for pulmonary PMN recruitment in mice suffering from TRALI and that targeting OPN prevents the occurrence of TRALI. Another recent study demonstrated the importance of M1-polarized alveolar macrophages in murine TRALI induction by showing that α1-antitrypsin (AAT) overexpression prevented TRALI in mice through decreasing the polarization of alveolar macrophages towards the M1 phenotype.

SUMMARY

Apart from PMNs, macrophages also appear to be important in the pathogenesis of TRALI. Targeting the pathogenic functions of macrophages may be a promising therapeutic strategy to explore in TRALI.

Identifying and Understanding Transfusion Reactions in the Oncology Population

OBJECTIVES

To provide an overview of transfusion reactions, their underlying pathophysiology, clinical presentation, and recommendations for nursing management.

DATA SOURCES

We researched peer-reviewed journal articles, book chapters, Internet, and lecture proceedings.

CONCLUSION

Transfusion reactions are adverse reactions to blood products frequently seen in the oncology population and can significantly vary in severity and etiology. Oncology nurses are in a critical position to assist with prevention, early detection, and time-sensitive treatment of transfusion reactions.

IMPLICATIONS FOR NURSING PRACTICE

The oncology nurse's comprehensive understanding of possible transfusion reactions and management recommendations is key for optimal care of the oncology patient.

Bedside Allogeneic Erythrocyte Washing with a Cell Saver to Remove Cytokines, Chemokines, and Cell-derived Microvesicles

BACKGROUND

Removal of cytokines, chemokines, and microvesicles from the supernatant of allogeneic erythrocytes may help mitigate adverse transfusion reactions. Blood bank-based washing procedures present logistical difficulties; therefore, we tested the hypothesis that on-demand bedside washing of allogeneic erythrocyte units is capable of removing soluble factors and is feasible in a clinical setting.

METHODS

There were in vitro and prospective, observation cohort components to this a priori planned substudy evaluating bedside allogeneic erythrocyte washing, with a cell saver, during cardiac surgery. Laboratory data were collected from the first 75 washed units given to a subset of patients nested in the intervention arm of a parent clinical trial. Paired pre- and postwash samples from the blood unit bags were centrifuged. The supernatant was aspirated and frozen at -70°C, then batch-tested for cell-derived microvesicles, soluble CD40 ligand, chemokine ligand 5, and neutral lipids (all previously associated with transfusion reactions) and cell-free hemoglobin (possibly increased by washing). From the entire cohort randomized to the intervention arm of the trial, bedside washing was defined as feasible if at least 75% of prescribed units were washed per protocol.

RESULTS

Paired data were available for 74 units. Washing reduced soluble CD40 ligand (median [interquartile range]; from 143 [1 to 338] ng/ml to zero), chemokine ligand 5 (from 1,314 [715 to 2,551] to 305 [179 to 488] ng/ml), and microvesicle numbers (from 6.90 [4.10 to 20.0] to 0.83 [0.33 to 2.80] × 106), while cell-free hemoglobin concentration increased from 72.6 (53.6 to 171.6) mg/dl to 210.5 (126.6 to 479.6) mg/dl (P < 0.0001 for each). There was no effect on neutral lipids. Bedside washing was determined as feasible for 80 of 81 patients (99%); overall, 293 of 314 (93%) units were washed per protocol.

CONCLUSIONS

Bedside erythrocyte washing was clinically feasible and greatly reduced concentrations of soluble factors thought to be associated with transfusion-related adverse reactions, increasing concentrations of cell-free hemoglobin while maintaining acceptable (less than 0.8%) hemolysis.

EDITOR’S PERSPECTIVE

Phenotypes and personalized medicine in the acute respiratory distress syndrome

Although the acute respiratory distress syndrome (ARDS) is well defined by the development of acute hypoxemia, bilateral infiltrates and non-cardiogenic pulmonary edema, ARDS is heterogeneous in terms of clinical risk factors, physiology of lung injury, microbiology, and biology, potentially explaining why pharmacologic therapies have been mostly unsuccessful in treating ARDS. Identifying phenotypes of ARDS and integrating this information into patient selection for clinical trials may increase the chance for efficacy with new treatments. In this review, we focus on classifying ARDS by the associated clinical disorders, physiological data, and radiographic imaging. We consider biologic phenotypes, including plasma protein biomarkers, gene expression, and common causative microbiologic pathogens. We will also discuss the issue of focusing clinical trials on the patient's phase of lung injury, including prevention, administration of therapy during early acute lung injury, and treatment of established ARDS. A more in depth understanding of the interplay of these variables in ARDS should provide more success in designing and conducting clinical trials and achieving the goal of personalized medicine.

Complement activation on endothelium initiates antibody-mediated acute lung injury

Antibodies targeting human leukocyte antigen (HLA)/major histocompatibility complex (MHC) proteins limit successful transplantation and transfusion, and their presence in blood products can cause lethal transfusion-related acute lung injury (TRALI). It is unclear which cell types are bound by these anti-leukocyte antibodies to initiate an immunologic cascade resulting in lung injury. We therefore conditionally removed MHC class I (MHC I) from likely cellular targets in antibody-mediated lung injury. Only the removal of endothelial MHC I reduced lung injury and mortality, related mechanistically to absent endothelial complement fixation and lung platelet retention. Restoration of endothelial MHC I rendered MHC I-deficient mice susceptible to lung injury. Neutrophil responses, including neutrophil extracellular trap (NET) release, were intact in endothelial MHC I-deficient mice, whereas complement depletion reduced both lung injury and NETs. Human pulmonary endothelial cells showed high HLA class I expression, and posttransfusion complement activation was increased in clinical TRALI. These results indicate that the critical source of antigen for anti-leukocyte antibodies is in fact the endothelium, which reframes our understanding of TRALI as a rapid-onset vasculitis. Inhibition of complement activation may have multiple beneficial effects of reducing endothelial injury, platelet retention, and NET release in conditions where antibodies trigger these pathogenic responses.

Sex- and Gender-Related Factors in Blood Product Transfusions

Blood products are indicated for a plethora of conditions in several settings, with a variety of products available for transfusion, from highly processed specific components to whole blood. Matching the donor product to the recipient is crucial in avoiding serious transfusion reactions, with the extent of matching depending on the physiological need, setting, and product. There are important factors related to sex and gender differences in donated blood products, adverse reactions to those products, interplay with underlying pathology, as well as sociocultural differences in the collection. This article will review key sex- and gender-specific research related to the use of blood products with an emphasis on the acute care setting.

Platelet Activation and Endothelial Cell Dysfunction

In sepsis, coagulation is activated and there is an increased risk of developing a consumptive coagulopathy with attendant increase in mortality. The processes that regulate hemostasis evolved as a component of the inflammatory response to infection. Many points of interaction occur on the endothelial cell surface linking the 2 cell types in the initiation and regulation of hemostasis and inflammation. Consequently, inflammation stimulates both platelets and endothelial cells in ways that affect both hemostasis and the immune response. Platelets are also prime drivers of the inflammatory response. This article discusses the pathways wherein inflammation regulates platelet and endothelial cell function.